Early Primitive Elvish
ili
root. shine oily
ili
root. many
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A root in the Qenya Lexicon of the 1910s glossed “shine oily” with derivatives like ᴱQ. ilma/G. ilm “oil” and ᴱQ. ilin (ilim-) “milk” (QL/42; GL/50). The sense “oil” seems to have been transferred to a new primitive form ✶mḷgo in the 1920s (PE13/139). However, ᴱQ. ilin (ilim-) “milk” remains the only Elvish word for “milk”, and I think it is worthwhile to preserve this word by assuming the existence of a Neo-Eldarin root ᴺ√ILIM of this meaning. The root ᴱ√ILI might have reemerged in a 1968 note as √LIP “oil” as suggested by Wynne, Smith and Hostetter, but this new root had no derivatives given (VT44/15, 20 note #7).